Train control



PIC-1.1.

July 9, 1929.

W. K. HOWE TRAIN CONTROL Original Filed Oct. '7, 1922 4 Sheets-Sheet l w/zw ab/ATTORNEY July 9, 1929.

W. K. HOWE TRAIN CONTROL Original Filed Oct. '7, 1922 4 SheetsSheet 2 lav zd/am ATTORNEY July 9, 1929. w, HQWE 1,720,633

. TRAIN CONTROL Original Filed Oct. '7, 1922 4 Sheets-Sheet 3 w. K. HOWE TRAIN CONTROL July 9, 1' 929.

Original Filed Oct 7, 1922 4 Sheets-Sheet 4 fill Patented July 9, 1929.

U T D STATES PATENT OFFICE-1;;

wmrnaorx HOWE, or nocnns'rnnnnw roaxiassmnon 'ro GENERAL RAILWAY SIGNAL COMPANY, or GATES, NEW YORK, A CORPORATION OF NEW YORK.

f comma Application filed October 7, 1922, Serial No." 593,073. Renewed November 25,1927.

This invention relates 'toautom'atic train control systems, and particularly to a system wherein a plurality of distinctive intermittent control influences are transmitted from the trackway toa moving vehicle.

In providing apparatus for automatically controlling a train, or for bringing it to a stop if it exceeds a safe speed at a'particular point along the track under either clear or dan er traflic conditions ahead, itis found desirable to'limit the train to a certain speed continuously for a certain 4 distance after which the speed limit mayj'be stillinore restricted until the speed is reduced to a safe value at that particular point along the trackway. If, for instance, 'it isdes'ired to bring the train to a safelo'w Speed of, say, ten miles per hour, it is'de'sirablelto' radually bring the train down to this'speed y successive steps of decreasin g speedlim'its which are enforced by distinctive controlinfiuen'ces from the trackway uhtilfthis low'speedlimitis reached. This manner of' bringing the speed down is desirable, becausethe' successive" decreasing speed limits 'r'na'y beeniorc'ed relatively close together or far apart, in accorda'ncev with. the ability of the train tostop in this particular section of the trackway. For instance, in a section where there is a steep downgrade, the successive lower speed limits must be enforced further apart/on'accouritof-the longer braking distance necessary on'down'grade to allow the engineer 'prop'er controlof the train to prevent an automatic brake application,wl 1ereas on an upgrade and around a curve a much shorter braking distance willbe sullicient, and the successive speed limitsmay be enforced much closertogethei'. Further, a speed limit ma be enforced at a particular point in abloc entirely independently of a preceding speed limit, by asystem of this kind. r

I In applying automatic devices for controlling the movement-of mats in accordance with trai'lic and trackway conditions in ad vance, it is desirable, for well-known reasons, to use the regular air brakesystem already on the train; but difliculti'es are 'encountered in enforcing an automatic brake application with safety and in a. manner so that it can not be toreslalled.byv the'engineer. In order to make a brake application by suitable auto- .ll'lkltlC apparatus acting upon the usualair brake equipmenhit is necessary to vent air from the brake pipe. 1 Since, however, the engineers brake valve when in its usual running" position continually feeds air into thebrake pipe through a feed valve itis advisable to do more than merely open the brake pi e to atmosphere to cause aproper brake ap ication, that is, a brake a plication which Wlll not en able the triple va ve located on the cars of the following train to move into emergency and apply the brakesso severely so as to endanger the railway equipment. In addition to the undesirable feature of the automatic airmind, the principal objects and purposes of the present invention contemplate the provision of suitable devices on the railway vehicle which are adapted to be inductively influenced by suitable traific controlled devices along the trackway for transmitting dist-inctivc control influences through an"air;gap, and without physical contact between such devices; to provide apparatus 0n the vehicle which will set up permissive speed limits corresponding to these distinctive control influences, each speed limit persisting until changed by the reception of another control influence; to provide a brake applying device which will act upon the regular air-brakesysftem' through the agency of the regular engineers brake valve 'and which will apply the brakes automatically whenever operated, ir-

rcspecti-veofan effort on the part-of the engineer to prevent such brake application;

and to provide means whereby an automatic application of thebrakes of the vehicle will nottake place, provided the engineer isapplyingthe brail'r es' or hasapplied the brakes to a redetermined extent and keeps them onto this extent .i11itil"tlie speed is safe, whereby the step-by -stepor saw-tooth speed limits may be smoothed out-,I'so to spealgthereby allowing the train speedto exceed the permissive speed when it is first enforced, and whereby the action of the brakesthelnselves'will bring below such permissive speed limit before the point along the track will be reached where the next lower speed limit will i a I ..'by' direct engagementrotparts,but can not be moved to" the release'position by such clibe-enforced.

A further important object'and purposeof this invention is to provide an organization of U parts constituting a speed control system which, while affording the engineer all .rea

sonable opportunity and latitude to control the trainhimself, will automatically apply the brakes in case the trainis not being properly controlled and also impose a suitable penaltyupon the engineer for permitting the automatic brake applying mechanism to work.v In other Words, the system embodyingthis invention is designed with. the idea of maintaining as far as possible the vigilance and care with which engineers with rare exceptions observeand act, upon the indications of the block signals, in order that the ultimate safety of the train is safeguarded by the vigilance and care of the engineer and efficiency and dependability of the block signal system inthe'first place, supplemented by theprotection, affordedby the automatic speed control. equipment. The penalty imposed on the-engineer for his neglect or misjudgment in allowing the automatic brake applying mechanism to work may take various forms, such as subsequent discipline based upon recording each automatic brake operation; but it is preferred to use what maybe termeda self-inflicted.penalty. enforced at thesame time as the. default by compelling the engineerto bring his train to a stop in order to proceed in the. event that the automatic mechanism causes abrake application.

As previouslyexplained, it is contemplated in accordance with this invention that the permissible limiting speeds will beset up to conform with distinctive control influences received from the trackway at the appropriate points and since the number of these that can be provided only roughly approximate. the speeds at which the train may safely rung. Consequently, if the engineer controls a speed of his train in the ordinary way in. slowing down, in

obedience to a,caut1on signal, it may. well happen that, while the engineer is properly regulatlng the speed of his train, he will exceed the permissible speed limits set up by the automatic system; and it is proposed 1n this invention, .to obviate this difficulty by ,constructingthe car apparatus in such a way that the engineer, by applying the brakes himself and maintaining that brake application until the speed has been safely reduced, may avoid the,au tomati c brake applicat on .and the resultant penalty. 1

i To provide the brake applying device .mentioned, it.is contemplated to-modify the usual engineers brake valve of the standard Fig. 5 is rect engagement, but merely through the medium of an intervening initially tensioned spring, providing such movement is not op posed by a suitable automatic' brake valve operator whichis moving toward, or is holdingthi's valve, in the service brake applying pos tion. "'1' Further objects,p'urposes, and characteristic features of-the invention willappear'as the description thereof progresses. In describing the i'nven'tion 'in detail, ref- -erence will be made to the accompanying drawings, in which v Figure 1 illustrates a portion of'a railway track along which are provide'dsuitable inductive influence transmitting devices for transmitting distinctive control influences to suitable car-carried e'quipihentQand showing a step-by-step speed distance curve enforced by such trackway devices .Fig. 2 illustrates ina d'agrammati'c manner car ca'rrie'd .equ'ipment adapted to cooperate with the trackway equipment shown'inFig.

ll'to enforce speed limits in accordance'with such speed distance curve; p v

' Fig. 3 is a'plan'view of the usual engineers brake valve provided with an automatic brake valve operator embodying a feature of the present invention, portions thcre ofibeing shown in secti'oin'and taken on the line 33 .of Fig. 4;

Fig. etis a partial section taken on the line 4-1-4," F ig."3, as viewed in the direction of the arrows;v a cross section taken onthc line 55 of Fig. 4; and

. Fig. 6 'shows a car-carried circuit arrangement substantially the same as that shown' in Fig. 2 but employing modified influence receiving elements, and modified track elements adapted to cooperate therewith.

Tlie' preferred embodiment of the present invention relatesparticularly to means for transmittinginfluences, which are distinctive n" character, from suitable trackway devices located unsymmetrically with respect to the track, so that the movement of a train equipped therewith when moving against the normal direction of trafiic will not be affected thereby, and which communicate with a singlc car-carried'device adapted to cooperate therewith. The trackwa y equipment for such a system is shown in Fig. 1, which shows the usual rails 1 of a railway'track divided into blocks by insulated joints 2, the block I and the adjacent ends of. two other blocks H and J being shown. Since the several devices in each block are the same, they have been given the same reference characters with distinctive exponents. The block I, asshown, is

.core 5, preferably of laminated magnetic-ma- .terial, tcrminating inenlarged pole pieces 6 .erably of low resistance.

providedwith'a track battery 3 and a track relay 4 top'rovide-the usualclosed track cir cuit controLi The influence-transmitting de vices of 'a traincont-rol system embodying the present invention. comprise in general a short U-shaped-knocksdown track element T at a point alongthe track where .the first restriction-in speed is to be enforced under caution traffic conditions, a longerU-shaped influence transmitting track element T" located ato=a point where the next lower restrictive speedvis to be enforced, and a three-legged trackway element T where the third and next lower restrictive speed isto be=enforced, another resetting-traek element TR-being provided at the endof a block for removing the restrictionsenforced by any, or all,.-of the traek-elements T, T andiT, providing the next block in advance thereof-is clean:

The traclqele'ment T comprises a U-shaped andprov-ided with a coil-7, whereasthetrack .elementzT comprises a.- similar U-shaped core S-termmatmgin enlarged pole pieces 9, which are spaced substantially twice the distance between pole pieces 6,:zand. :is also provided .with .a coill0.- The! track element T coni- Adjacent-each of the track elements T,

'l. and T, is. provided a=:i'epeater line relay 17, having a front contact '18 connected across the coils onrthese respective track elements. These repeaterrelays 17 are connected between a=linevwire;19 and 'a commonureturn wire C (not shown), and'la re energized from a suitable source of 1 energvhcontrolled by a front contact :20. of the track relay 4 ofthe next block in advance, having its other ternnn al connected to saidcommon return wire C. It should :be noted that under clear trafiic conditions Cofthe block J "each of the track elements T, T and T :will-havctheir coils closed in a deenergized circuit whichis pref- The. resetting track element TR comprises a U-shaped core 21 of laminated magnetic material terminating in pole pieces 22, and provided with a coil 23011 its back yoke. This resetting track-element TR. at the exit end of the-block is' under normal conditions, that is, when the next-block in advance is clear, energized by the battery 24' through a circuit which may be traced as follows :beginning atuthe battery 24, wire 25, front contact 26 01 the track relay 4, wire 27, coil 23 of theresettingtrack element TR, wire'28back to the The system is preferably used in'connection with the usual-fixed signals, and these signals may be of the semaphore, color-light, position-light, or other suitable type; and in the simplified arrangement shown in Fig. 1,- three-position semaphore signals Z have been shown in a conventional manner without illustrating their well-known control circuits and devices, it being understood that these semaphore signals will indicate clear, caution and stop in the usual way dependent upon the presence and absence of trains in the corresponding and the next block in ad- Vance.

mThe several car-carried devices which cooperate throngh suitable circuits to enforce several distinctive speed limits, by cooperation with the trackway devices shown in Fig. 1, will first be separately referred to, after which the manner in which they cooperate will be described in detail. Of these devices the automatic brake valve operator will first 'be described in detail.

.w Brake cal 0e opemzf0nReferring to Figs. 3 to 5,- the automatic brake valve operator 'consists of a casing 30 provided with a tubular extension forming an air cylinder 31. -'This operator casing 30 is provided with a flange 32 corresponding to the flange of the usual engineers valve cover plate, and is bolted to the casing 33 of the usual engineers brake valve. This casing 30 is provided with apartition 34, having a flange 35 to form a hearing. The usual rotary valve 36 is shown extending into the casing 30, and is provided with a squared recess to receive the squared end 37 of the valve stem 38.

This valvestem 38 is provided with a re cessed flange 39, in the recess of which is provided a packing ring 40. A compression coil spring 41 is provided in the counterbore of the square portion 37 of the valve steinv 38 and bears against the rotary valve 36 to lift the valve stem 38 up against the E partition 34:. The valve stem 38 is also forced upward by main reservoir pressure air, which is provided inthe casing 30 below the partiition 3-it 1"or urging the rotary valve 36 against 'its seat in' the usual manner.

1 Rotatablymounted on the valve stem 38 is a. gear sector 45, which is in operative en- 1 gagement with a rack 46 guided by guides '47 and 48, and having its opposite end fastened to a piston 49 contained in the air cylinder 31. A compression coil spring 50 is provided between the piston 49 and the inwardly extending flange 51 of the air cylinder 31. This spring 50 normally maintains the sector 45 in its normal position as Shown, but WillbG compressed to allow the rack 46 to operate the gear sector 45 in a counterclockwise'di-rection when pressure fluid is radniittedto the air cylinder 31.

Directly above the sector 45 the valve stem 338 'is provided with a squared portion on which is slidably but non-rotatably fitted a valve stem collar 0, which is provided with a downwardly extending lug 53 which is adapted to be engaged by the edge of the secresilient contact fingers 58 fastened under --the headsof binding posts 59. The relation of the contact segment 55 to that of the contact fingers 58 is such that these contact fingers will be bridged by the segment only if the val-vefstein collar and rotary valve 36 are in a brake applying position, either service oremergency, or both. The valve stem 38 is provided with a cylindrical extension onwhich is pivotally 10111- =naled aliandle stem 60, and this handle stem is provided with a. flange 61 hearing under the cover 62 screw fastened against the casing '30. -This-handle stem .is provided with a radially-extending screw pin 63, which is urged against an upstanding lug 64 on the valve stein collar C by the action of a. coil 'spi'ing'65, this spring having its one end fastened to the handle stem 60 by a screw '66, and having its other end hooked around the curved lug 67 extending from the collar C. It will thus be noted that counter-clock- .wise rotation of the handle stem 60 causes positive engagement between the screw pin 63 and the lug 64, whereas clockwise rotation of the handle stem 60 provides an operative connection able to transmit a torque equal to the initial tension of this spring only. The portion 70 of the handle stem 60 extend ing from the casing is squared, and provided with the usual brake valve operating handle 71 which is provided with a spring latch 72 -adapted to engage suitable notches 7 3 correspondmg to the running, holding, lap and service positions of this handle respectively. The flow of air pressure to the air cylinder -31is-controlled by anelectrically operated pneumatic valve designated E. P. V. This valve E. P. V. comprises a casing 75, having partitions 7 6 and 77 to form compartments 78,

79 and 80 respectively. The top wall of the E. P. V. is provided with a threaded opening in which is contained a screw plug 81 which slidably' supports the end of a valve stem 82,-having an-armature 83 fastened to the lower-end thereof and adapted to be held in its upper and normal position by a coil 84. This valve stem 82 is provided with valves 85 land 86 adapted to rest on valve seats in thepartitions'? 6 and 77 respectively, the valve. 85being closed when the coil 84 is energized and the valve 86 being closed when itliiscoil is dcenergized. The compartment .78 is connected to the main reservoir of the usual air brake system-by a pipe 87, whereas the chamber 79 is connected to the air cylinder 31 by a pipe 88, and the chamber 80 .is connected-to atmosphere through the opening 89. It is thus readily apparent that the air cylinder .31 will beconnected t'oatmosphere when the coil 84 is, energized, butwill be connected to main reservoir pressure when this condition, main reservoir pressurewill flow through pipe 87,-chambers'i78 and .79,

through pipe 88 into the air cylinder 31,

thereby compressing spring 50 andoperating the sector 45 in a counter-clockwisedirection.

Assuming that the brake valve is: at this time in its normal running position as shown,

the initial or first part of the movement of the gear sector 45 willido nothing toward operating the valve. After this initial movement, the edge of the gearzsector 45 will engage the downwardly extending lug 53 on the collar C, thereby carrying this collar 0, the valve stem 38 and the rotary valve 36 tothe service brake applying-position lof thisvalve, the rack 46 being-limited from further movement by striking the wall of the casing 30. It will be noted that this movement of the collar C will further tension the spring 65 if the handle 71' will not follow the movement of the collar C. It is contemplated, however,-

that the initial tension of-thisspring 65 shall be sufficient so that an automatic. operation of the collar C will cause thisspring to carry the handle 71 with. it to the service position, but will not be strong enough so that if the engineer either holds thehandle or moves it to the release position-that this springwill prevent the movement of the rotary valve 36 to the servicebrake applying position by the automatic apparatus. i Assume now that'the engineer has notlield the handle 71, and thatrit has been moved to the service position, so that the spring latch 72 engages the service notch. Assume further that the train-has been brought to a safe speed, and that the coil84 is again energized by the automatic train control equipment to be described hereinafter. The energization of the coil 84 cuts off main'reservoir pressure from the air cylinder 31, and connects thiscylinder to atmosphere through port89. The

release of pressure from the air cylinder 31 allows the spring 50 to move the rack 46 and gear sector 45 back '-to their original and normal position. The rotary valve 36 will, how

ever, not be returnedtbecauso? there ;is n mechanical connection between the-sector and the collar C for clockwise'rotationz-of this sector 45.. If the engineer nowwishes to release; the brakes, he may do' so by moving the brake handle to the release. o'sition and then to'the running position, in he usual manner. 'T v Let us assume now that an automatic sen ice brake application has been effected,-as just explained, and that the engineer desires to do still more towardcstopping the train. This may be done by operatingthe brake valve handle 71 to the emergency position,,there being no interference between the'collar C and the gear sector 45 for counter-clockwise rotation of this collar C. Aftersueh a brake application, the brakes may again ,be released manually in the same manneras heretofore, as soon-as the coil St is again. energized. Oar-carried control app(1 1'atus.,.-In' addition to the automatic brakeyalve operator already described indetail, the ear-carriedapparatus includes a knockndown car element KD. This car elementKD comprises a threelcgged core, preferably constructed of lami.- nated magnetic material, comprising whack yoke 90, having legs 91,92 and 93= terminating in enlarged pole ;pieces9t.-. The leg 91 of the car elementfKD is providedwith a primary coil P, =whereas the 1egs92 and-93 are provided with secondary eoils S antl-S respectively; This car element KD is preferably located on the right side of the-vehicle facing in the direction of traific,.and ispreferably mounted so that the pole pieces 94 have a definite relation to the track elements with which it is to cooperate. This mount.- ing of the car element is preferablyaccomplished by housing it in a suitable light nonmagnetic casing, suspended from the side frame of the truck, or other suitable part of a vehicle, by an initially tensioned spring .device, and having a definiterelation-with respect to the track. I i

A reset car element RD is provided which comprises a U-shaped core of magnetic material, having legs 95- terminatinin pole pieces 96. A portion of the back yo eof this U-shaped core is preferably cutaway to provide an air gap, inWhie-h is pivotallygs upported an armature 97 by a-spindle 98 and maintained in its openor retracted-position by a spring 99. To this armature 97E is-fastened, but insulated therefrom, a noyable contact 100, which in the attracted 1 position of the armature 97 is in 'eontactwith astationary contact shown conventionally by the arrow 101.- This reset car clement-RD is preferably supported in a manner similar to the knock-down element KD.

The car-carried equipment also includes two control relays CR- and CR a high speed relay HR, an intermediate speed relay IR,a low -speed relay LR in addition to a pickup construction-causes the jars and "ibration of v the vehicleto be a certain extent absorbed and transformed-by the heavy casing and spring support; thereby preventing such disturbances from reaching the relays and interferringwiththeir operation.- s

. .In order to enforce a continuing permissive speed-limit, a suit-ablespeed responsive device or governor G hasbeen provided. This governor (it comprises a shaft 103 operatively connected t0,and driven-by, the wheels of theivehicle. On the shaft:103 is pinned a collar ltlgiandnis alsoislidably supported another collar 105 provided with a peripheral groove 1,06, which is engaged by an angle lcver.10 7 having: an extending arm; 108 connected thereto, but insulated therefrom bytinsulation. 1.09. 'The collars 104 and 105 are connected together by links 110 and 111,, having a weight 112at the point of their pivotal connection. A -con'ipression coil spring 113 is provided on the shaft 103 between the collars'104 and 3105 for spacing these collars the distance permitted by the links 110 and 111. It is thus seen that upon rotationof the shaft 103, the weights 112 will separate due tothc centrifugal gtorce exerted thereon, whereby .t-lie-rollar 105, will be moved downward agai nst the tension of the spring 113,'thercby moving thearm 108 toward the right over the stationary cont-act segments 114,, 115, 116 andll'i. 1 ,i

A suitable pneumatically,.operatedcircuit closer has been provided for closing a circuit when the pressure in the --brake cylinder of-thc air-brake s-ysteinihas reached. a certain value. This pneumatic circuit elosenhas been conventionally designated PC, and comprise a CylEi'IIClBI'YLQO provided-withacover 121 and having a piston 5122 fastened to the rod- 123 passing through-the cover 121. To the-end of the rod 123 is fastened,.butinsulated thereitrom, a1 contact 124 adapted to bridge stationary! contacts 125 as the piston 122 is moved toward the left. rL-compression coil -.spring 126is provided between the 'piston122 and the cover 121, so that'a prcdeterminedamount -ofp ressure pin the brake cylinder exerted upon the piston122 through the pipe 127. is necessar-y hefore the contacts 125 willhe bridged byitlMHCOQtfiiCt 12 1. I It isthus'seen, that a ,lOO

133,134, wire 148, winding of the control relay CR circuit'may be completed when a predetermined amount of pressure has been applied to"thebrake cylinder.

Another element of the-car apparatus con- ,sists of "a'suitable resettingdevice by which the engineeryafter an automatic brake appli cation, may restore the changed parts of the car equipment; This resetting device is shown in the form of a simple spring reset switchRS having normally open-contacts and normally closed contacts. This switch RS is preferably solocated as to be accessible only from the ground, in order that the engineer must. bring his train to a stop before the "switch can be actuated. It should be understood, however, that manipulation of this reset switch RS may be safeguarded in other ways, asby placing it in a locked box, the key of 'Whi'ch'is held by the conductor or someone else, or by sealing this switch or attaching a recording device, so that the railway oflicials 'may tellif this switch has been worked and can discipline the engineer;

' Operation of devices shown in Fig. 2.- Under normal conditions, that is, with the ve- ;hic1e equipped with the apparatus illustrated in'Fig. '2 in its normal condition, as shown, and moving in a'clear block along a trackway system, such as'illustrated in Fig. 1, the primary 'coil P of the knock-down element KD is'energized'through a circuit which may be 'tracedas follows :beginning at the battery 130, wires 131,132,133, 134. 135, 136, 137 and 138,'p'rimarycoil P, wire 139, winding of the check relay CK, wires140 and 141 back to the common return wire 142 connected to the other side of the battery 130. I This check relay CK is provided with a front contact 143 connected in series'with the winding and stick contacts of the E. P. V., so that if the current through the primary coil P should be entirely interrupted or should be too low due to depreciation ofthe battery, or the like. to supply the necessary amount of magneto-1notiveforce in the element KD, this check relay will drop its front contact 143, deenergize the E. P. V.,and' apply the brakes in the usual manner.

Under normal conditions, the control relay CR is energized through a circuit which may be'traced as followsF-beginning at the battery 130, wires 131, 132, 133, 134,135. 136, 137 and 144, secondary coil 8, wire'145, winding of the control relay CR wires 146 and 210 to reset switch RS, and wire 211 back to the-common return wire 142.

The control relay GR is energized through a circuit which may be traced as follows beginning at the battery 130, wires 131, 132, 135, 136 and 147, secondary coil S wires149 and 210, reset switch RS, and Wire 211 back to the common return wire 142.

With the control relay CR energized, a stick circuit is completed through the high speed relay IR is completed, which may be traced as follows beginning at th'e battery 130, wires 131,132 and 157, front contact-1 58 of the control relay CR wire 159, front'co'ntac't'lGO of the intermediate speed relay IR, wires 161 and 162, winding of the intermediate speed relay IR, wire 163 back to thec'om mon return wire 142. i I

A stick circuit for-the-low speed relay LR is a 'lso completed when either one of therelay's CR or GR is energized, whichmay'be traced as follows :beginning at the battery I30, wires 131- and 132, either thioiighthe front contact 151 of the control relayGR or'the front contact'158 of the control-'relay CRfl'a's the case may be, to wire 164, front contact 165 of the low speed relayLR, wires 166 and'167, wiiuling of the low speed relay IJR, wire 168 back to the common return wire 142. It is thus seen that the energizing circuit for the low speed relay LR will only-be brokenwhen both the relays CR and CR are simultaneously deenergized.

lVith each of the relays HR, IR, and DR energized, a high speed circuit for energizing the electro-pneumatic valve E. P." V. is completed, which may be traced as follows :beginning at the battery 130, wires 131 and 170, front contact 171 of the low speed relay, wires 172 and 173, front contact 174 of theintermediate speed relay IR, wires 175 and 176, front contact 177 of the high speed relay HR, wire 178, high speed contact'117 of the speed responsive device, movable contact 108, wires 179 and 180, front'contact 143'of the check relay CK, wire 181,- windingof the'device E. P. V.,'w1res '182 and 212 stick contact '74 of the E. P. V.,-and wires 213 and 141iback latter circuit completed, the train may assume a'speed up to andincluding, say, sixtymiles per hour, as s'hownin the speed-distance curve illustrated in'Fig. 1 of the drawings; Let us-assume now that" a train equipped with the apparatus illustrated in Fig. v2 is entering the block I when the next block J in advance is occupied by'another train. Under this condition, said another train'in the block J will shunt the track relay 4, thereby causing itto drop its front contact, thereby deenergizing the repeater "track relays 17 and in turn open-circuiting the coils 7, 10 and 16 01 the track elements T, T and T respectively.

As the train passes-by the first track element T" and at the time that this track element to "the commonreturn wire 142. 'VVith this bridges the pole pieces of-thelegs 91 and '92 of the knock-down car element KD, a sudden increase of flux will take place through the magnetic circuit including these two legs, this flux again decreasing to its normal value as the'car element KD recedes from this track element. This sudden increase and decrease of flux through the secondar coil S, which is partly due to diversion of ux from leakage paths and partly due to a momentary increase of the total flux through the primary coil P, generates a single cycle of E. M. F. in the secondary coil S similar to that of a cycle (if alternating current. The secondary coil S is so connected in the circuit with respect to the battery 130 that the first half cycle of this unicycle of E. M. F. will oppose the voltage of the battery 130, thereby decreasing the current flow through the control relay CR sufficiently to cause it to drop its armature and momentarily open its front contact 151. This momentary opening of the contact 151 will interrupt the stick circuit of the high speed relay HR, which will drop its front contact 153 included in this stick circuit, thereby deenergizing this relay HR permanently until reset by some other means. This permanent deenergization of the high speed relay HR permanently interrupts the high speed circuit heretofore traced including the front contact 177 of this relay, and the speed must be below, say, forty-five miles per hour as shown by the dot-ted line 183 of Fig. 1 in order that the device E. P. V. may receive energy through the intermediate speed circuit, which may be traced as follows z-beginning at the battery 130, wires 131 and 170, front contact 171 of the low speed relay LR, wires 172'and 173, front contact 174 of the intermediate speed relay IR, wires 175 and 184, contacts 116 and 108 of the speed responsive device G, wires 179 and 180. front contact 143 of the check relay CR, wire 181, winding of the device E. P. V., wires 182 and 212, stick contact 74, wires 213 and 141 back to the common return wire 142.

Let us assume now that the train has reached and is passing by the second track element T under caution tratlic conditions. The passage of the knock-down element KD over this track element T" causes a sudden in crease and decrease of flux through the leg 93 of the car element, similar to the change of flux through the leg 92 as heretofore explained. This sudden increase and dexarease of flux induces a single cycle of E. M. F. in the secondary coil S which momentarily deenergizes the control relay OR for reasons heretofore explained in connection with the control relay CR This momentary deenergization of the control relay CR momentarily breaks the stick circuit of the intermediate speed relay IR, thereby permanently deenergizing this relay due to the opening of the front contact 160 included in its stick circuit. This relay IR will, therefore, remain permanently deenergized until again reset by some other means. The deenergization of the intermediate speed relay IR opens its front contact 174, thereby interrupting the intermediate speed circuit through speed responsive contact 116. If the speed is below thirty miles per hour, as indicated by the dotted line 185, the device E. P. V. will be maintained energized through alow speed circuit which may be traced as follows :-beginning at the battery 130, wires 131 and 170, front contact 171 of the low speed relay LR, wires 172 and 186, segment 115 and contact 108 of the speed responsive device, wires 179 and 180, front contact 143 of the check relay CK, wire 181, winding of the device E. P. V. wires 182 and 212, stick contact 74, wires 213 and 141 back to the common return wire 142.

Let us assume that the train continues to pass through the block I under caution traffic conditions between the second and third track elements at a restricted speed of less than thirty miles per hour. lVhen the knockdown car element KD passes over the track element T", which is a three-legged element similar to this car element KD, a sudden increase and decrease offiux will take place through both the legs 92 and 98 of this car element KD. This sudden increase and decrease of flux through the secondary coils S and S simultaneously induces a single cycle of alternating current E. M. F. in these coils, the first half cycle of which is in a direction opposing the electro-motive force of the battery 130 and is high'enough to momentarily decnergize both the contrbl re lays CR and CR The simultaneous deenergization of both of these relays interrupts the stick circuit for the low speed relay LR heretofore traced. The momentary deenergization of this low speed relay LR causes it to drop its front contact 165 included in its stick circuit, thereby permanently deenergizing it until reset by suitable means. The permanent deenergization of this relay LR interrupts the low speed circuit including the contact segment 115 of the speed responsive device, and the device E. P. V. can be maintained energized through minimum speed contact 114, at a speed such as indicated by the dotted line 187 m Fig. l-of the drawings, which in the particular case shown is assumed to be fifteen miles per hour. In order to cause substantially the same change of flux through the legs 92 and 93 of the car element KD when passing over the track element T, the leg 13 of this track element may be slightly shorter than the. leg 14 so that the reluctance through both of the magnetic circuits including the leg 13 and leg 14 respectively may be substantially the same.

The train having now reached the end of the block will be permitted to enter the block J at this low permissive speed of fifteen miles winding of the high speed rela yHR, \vire be noted that a step-by-step or .be enforced .by

per hour, unless the bloek J has changed to a caution or elearblock. Let us assume that said another train has passed out of the block J into thefollowing block. Under these conditions, the track relay & will again be energized, thereby closing the circuit including the battery 24 and coil 23 ot' the reset track element TR heretofore traced. As the train proceeds and thresct device-RD on the vehicle passes over the reset track element Tll fiu:; ,frjo'i-nthe track element TR will permeate the legs of the reset device R1), thereby turning the armature 97, and momentarily completing a circuit through the pick-up relay PR, which maybe'traced as follows :begi n- Iiing at the battery 130, .wires on, ma, 133,131, 135 and 190, movable contact 100. stationary contact 101 of the reset device RD, wire 191, winding of the pick-up relay PR, wire 199 back to the common returnwire 1&2. The momentary energization of the pick-up-relayPR momentarily closes the contacts 193, ;1951,-and'195 of this relay. v

The momentary closure of. the'itront con- ,tact ;195 closes aipiek-up circuit for. the high speedrelay HR which may be traced as -followsr beginning atthe batteryv 130,, wires 131,196,197 and 198, front contact 195 of PR, wires 19!) and 155. 156 The the pickup relay back to the common return wire 112.

control;relay CR being energized causes tl high speed relay HR to become permzniently energizedaf-ter being momentarily energized through the pickup circuit just traced.

In asimila-r manner the intermediate relayIR and low speed relay LR may be momentarily energized by the following piclc up circuits :.(1) beginning at the battery and 200, front conancl 162,' winding of the intermediate relay IR, winding 163 back to the common return wire1142; (2) startingat the battery 130, wires 131, 196 and 202, frontcontact 193 of the pick-up relay PR, wires 203 and 167, winding of the low speed relay LR, wire 168 back tothe common return wire 142. The relays. HR. IR and LR- having again been energized, the train is allowed to proceed into ,the block J, restricted only to the maximum speedvlimit upon entering, and allows it to pass therethrough in accordance with the speed limits enforced in this block J (lependent upon traflic conditions ahead.

In looking at Fig. 1 of the drawings, it will saw-tooth speed-distance. permissive speed curve will the apparatus thus far described. For theparticular block shown in Fig. 1, a, certain grade, weight of train and braking power being assumed, the speed-distance curve 188 is intended to represent the speeds at various points in the block at which, if a service application of the brakes is initiva-t'ed, the train will be brought toa stop at or before reaching the' end ofthe ibloek. In other words, the curve 188- represents' a brake application curve :and shows grziphicallythe speeds at the:various points ,in-itheiblockeat which the brakes should' be apjjlied,;eith'er manually -orautomatically, in; order assure stoppa-geof the train initime.

The several track elements; iT tandT", sctti n g up the differentpermissive speedlimits hereinb'etore described, are located along the t ra ck with respect to. the 2b rakei application curve 188 in such a way that a train observing the speed limits autoinatica-llyprescribed will be controlled on the side ofsafety. The horizontal lines 183, 1S5'and 187 representthe speed limits, high, -medium and minimum, pre-ecrilxd; by the systeim 'lhetrack-inductor '1 is located at such a'point. as Zshown,

that a traintraveling at; the-medium speed various track elements or-inductorsanayibe varied to suit theditl'erent brakingicondi- Lions in the several blocks. 'Also, it shouldbe ,uiulerstrmd that the speed limits may be different for passenger and freight: trains, or trains having different braking; powers. 1

From consideration of -.the permissive limiting speeds shown in Fig. 1, it can'be seen that the step-by-step or saw tooth :line set up represents at some points speeds lower-than necessary for safety. a or example,aat "the track inductor fl, while the speed limit" set up at this point. is, say, vforty tive.imilesfper hour as represented by thealine183,thetrain could be traveling at highers'peeds at seve'ral points near said inductor and still be stopped in time. The same true ofthe-speed liniits set up at the inductors T and T Consequently, if the engineer is guided'l ry thelodation of the signalat which? he is to stop, and

delays his brakeapplication'witheduolregard to his speed and braking-power, he=is likely to exceedthe permissive speed l1m1tsset up,

more particularly at the t'rack'inductors themselveslwhere the permissive speed limits-are abruptly changed to lower 1 speed limits. should also be recognized thatvthe brake application curve 188wvill, in the interests of matieallyprescribed.

In order to maintain the Vigilance ofthe engineer, as previously explained, it is con s'idered'desirable to impose a penalty every time an automatic brake application occurs, but it will be clear that such penalty can not be fairly and justly-imposed unless the engineer has a reasonable opportunity to avoid the automatic brake application. Consequently, if the speed limi s required y the automatic train control system are unnecessarily low for safety, as previously explained, the engineer must adopt some unusual way "of braking his train, with the'resultant decrease in facility of the train movement, or

else he is likely to be penalized, although properly controlling the train with due regard to its braking power and the stopping point.

For these reasons, among other things, provision is made according to this invention so that, if the engineer is himself making aexisting, however, only so long as the engineer is himself effectively retarding the train, or until the speed has been brought below the permissive speed limits.

Referring to Fig.

2, it can be seen that the electro-pneumatic valve E. P. V. will be inaintained energized and an automatic brake application avoided, irrespective of its control by the. speed control apparatus, if either of two conditions exist, namely, (a) the enginccrs brake valve is in a brake applying posi-' tion, such as service or emergency, so as to close contacts 58, or (1)) therei suilicient pressure in a brake cylinder to close contacts 125. If the engineefls brakevalve is in the service position, the brakes are being applied, and since the permissive speedlimits and the brake application curve 188 are based upon initiation of the brake application, it can be-v seen that whenever the engineer placeshis brake valve in the service position, the train will he stopped in time; even though it is eX- ceeding someone of the permissive speed limits automatically setup. Similarly, if there is effective braking already in force, as manifested by the existence of a predetermined amount of pressure in a brake cylinder, the train is being slowed down and will stop in time. Putting it another way, so long as the train is slowed down, after entering the caution block at a speed less than a maximum entrance speed, it is imn'iaterial whether this result is due to a manual brake application made by the engineer or by an automatic brake application, the train being slowed down in either case.

If the engineers valve is in the service position closing contacts 58, the'electro-pneupermissive .108117 reclosel' Afterthe speed has been may release the brake application; but .engineershould fail to apply the brakes or 'matic valve E. P. V. is maintained energized,

irrespective of the different speed circuitshereinbefore traced, by a circuit that may be traced as followsz-beginning at the battery 130, wires"131, 132, 133, 13%. through contacts 58 closed, wires 189 and 180 and through the front contact 14-3 of the check relay OK. the stick contacts and winding of the E. P. V., as in the circuits previously traced. Similarly, if there is a predeter mined pressure in a brake cylinder, sutlicient to overcome the spring 126, the contacts 125 are bridged. by the contact member 121, establishing a circuit forenergizing the device E. P. V. analogous to the circuit just traced.

Toillus't'rate the advantages of the arrangem'ent by which the engineer, by making "a manual brake application, may forestall or suppress automatic braking, assuming the train' exceeds the maximum normal running speed, if the engineer, realizing that his train is running too fast, has initiated abrake application, or already made a brake application, the movement of contact 108 out of engagement with contact 117 does not deenergize the electro-pneumatic valve E. P. V., which is maintained energized through the closureof contacts 58 or 125, as the case may be. \Vith the brakes being applied or fully acting, it i's'obviou'sthat the train must in time reduce itsspeed below the maximum speed, whereupon contacts brought down below the maximum normal running speed desired, then the engineer if the maintain the brakes applied until the desired maximum speed limit has been observed, then the electro-pneunmtic valve E..P V. will be operated, and an automatic brake application occur.

, Assume now that the train enters the block I show in Fig. 1 under caution conditions at a speed of, say, fifty-five miles per hour, This speed is higher than the speed limit of fortyfive miles per hour automatic allv setup at,the track inductor T. If the engineer alert and observes that he has passed a caution signal, and realizing that hisspeed is too high, initiates a brake application betore passing ,the' track element '1,

'the brakes will not be automatically applied,

even though the speed is above the permissive speed indicated by the line 183; and if the engineer properly maintains this brake application, the speed of the train will be reduced in the manner indicated by the dot and dash curve 205 as atypical example. If the trainfhas more braking power than indieated by the application curve 188, the speed under the manual brake application w illloe reduced faster than shown by the curve 205, but in any case the train willke-ep 206 as a typical instance.

below the application curve 188. 1 II" the engineerireleases the'brakes'before his speed has been reduced down to that indicated by the line 183, an automatic brake application occurs; but if the engineer keeps the brakes on until the speed has been so reduced, he may then release them it he desires. Similarly, a train may approach and pass the track element T at a speed greater than tact-s 58 or 125, are at any time broken and said valve is deenergized, its stick contacts M open, so that subsequent closure of either of these groups of circuits does not permit reenergization of said valve, which must be reset by manipulation of the reset switch RS. Consequently, whenever the electro-pneumatic valve E. P. V. operates to stop the train, the engineer is obliged to stop and reset from the ground, this being the penalty for his tailure to safely control the train. It will be noted that the reset switch RS, when actuated to close its normally open contacts, provides a shunt for the stick .contacts 7st of the device E. P. V. permitting this device to be picked up by one of its normal energizing circuits. Since the train must be at a standstill or must be moving very slowly in order to allow the reset push button ES to be operated, the contact 108 is in engagement with segment 114;, and with push button RS depressed the following reset circuit is closed :-beginning at battery 130, wires 131, 132 and 132, contacts 114108, wires 179 and 180, front contact 143 of the check relay CK, wire 181, winding of thedevice E. P. V. wires 182 and 182, de-

pressed contact RS, wires 211 and 142 back to the other sideoi' the battery 13 The reset switch RS can not be maliciously fastened down, because when itis shifted, its normally closed'contacts open and deenergize both of the relays CR and CR thereby establishing the minimum speed limit. In other words, if the engineer should endeavor to defeat the objects of the invention and avoid the penalty by fastening down the reset switch RS, his train can not proceed above a. minimum speed. Obviously, other expedients for protecting this reset device RS may be employed; and generally speaking, this switch, when actuated, may break any vital circuit limiting the speed of the train or preventing it from moving at all until said switch is restored to normal.

From the foregoing it can be seen that there is provided by this invention the simple and efficient arrangement in which, if the engineer is alert and whenever his speed becomes too high makes a manual application of the brakes, there is noaut-omatic braking, while if the engineer is negligent, eitherby exceeding normal speed, by failing to observe the restrictive signal indications and reduce speed accordingly, or by neglecting at any. time to maintain safe speeds or apply the brakes, an automatic application of the brakes is made to safeguard the train and the engineer is penalized for his neglect. Thus, not only is vigilance on the part of the engineer stimulated and in fact enforced in a practical manner, but the train is at all times automatically controlled on the side of safety, all this being accomplished without particular refinement in prescribing permissive speed limits for various blocks. Also, since the automatic application of the brakes will occur very rarely, since en ineers as a rule are alert and careful, the automatic brake application may be somewhat severe in its effect on the equipment, sliding the wheels, producing considerable jar and shock, and the like, because this automatic application will occur so rarely and then only in the event of a rea'l'emergency due to failure oi"; the engineer, that these effects may be tolerated.

Description 0 Fz'y. 6.-In Fig. 6 has been illustrated a modified form of the invention shown in Fig. 2 in which the car-carried devices and circuits are substantially the same with the exception of the knock-down car elements. Like devices and circuit wires have therefore been given the same reference characters. The principal distinction of this system from that of the one shown in Fig. 2 resides in the provision of two knock-down'car elements .KD and KD" instead of the single kruick-down car elcmentKD shown in Fig. 2. These knock-down car elements KD and KD comprise Ushaped cores of magnetic material terminating in enlarged pole pieces, on the one leg of which is provided a primary coil P", the other leg of the element KD heing provided with a secondary coil S, whereas the car element KD has its other leg provided with a secondary coil S These primary coils P are connected in series and in a circuit substantially the same as the primary coil P in Fig. 2, whereas the secondary coil S has been substituted lor-the secondary coil S and the secondary coil S has been substituted for the secondary coil S Anotl'ier distinction in the car-carried apparatus of this figure resides in the location of the reset device RI) with respect to the trackway, that is, it is located between the running rails instead-of being located on the left side of the vehicle, as shown in Fig. 2. Similarly, the trackway devices have been modified to properly cooperate with the car carried devices, .the reset track deviceTR'being located between the running rails, while U-shaped track elements 'T'H located on the right side .of the trackway and track elements TI located on the left side of the trackway have been provided to transmit a high speed knock-down influence and an intermediate speed knock-down influence respectively, whereas .a pair ofU-shaped track elements TL, ,one located on each side of the t-rackway havejbeen provided for transmitting a "low speed knock-down influence. Each of these track elements are provided with coils which tion with Figs. 1 and 2.

under clear traffic conditions maybe closed in a circuit of low resistance, substantially in the same manner as described in. connec- If desired, these track elements may be unsymmetrica'lly spaced with respect to the track rails so that the" vehicle equipped with the knock-down elements KI) and KD will not properly cooperate therewith after this vehicle is turned end for end. The operation of the system shown in Fig. 6 is substantially the same as that of the system in Fig. 2, and will be obvious to those skilled in the art after understanding the operation of the preferred embodiment'of this invention.

Although only two specific embodiments of the present invention have been illustrated, it should be understood that various modifications may be used to adapt the invention to various conditions encountered in prac tice without departing from the spirit and scope thereof. For instance, the trackway devices may be controlled in'any suitable manner dependent upon the block signal system in connection with Which they are used, that is, may be controlled entirely automatically using various forms of electrical energy for this purpose, or may be partly controll'ed'manually; or certain of the trackvvay devices may be made permanently effective so as to enforce lower speed limits through territory which has permanent hazards, such as curves, sudden down grade sections, drawbridges, and the like. Further, the ear-carried apparatus may be modified to apply it to the various trackway systems employed. For instance, the necessary modification may be made so that the same apparatus can be used when either end of the vehicle is running ahead, either for double track or single track systems, so that no control'influence will be received when running against the normal direction of traflic in either case; as is obvious to those skilled in the art.

lVhile there has been shown and described specific apparatus performing certain functions for accomplishing automatic speed control of'railway vehicles, this invention in a broader aspect represents a method of safemardingtrain movements, such method havmg well defined characteristics conceivable independently of any particular form of apparatus. To illustrate, irrespective of the particular equipment employed on the trackway or on the car, the invention in its broad aspect contemplates safeguarding the movement of the train and at the same time maintaining vigilance-on the part of the engineer by establishing atappropriate points along the track certain permissible speed limits, the change from one permissive speed limit to another being abrupt and not necessarily in conformity with the possible rate ofretardation of the train, and in automatically applying the brakes if any oneof these speed limits is exceeded at any time, unless the engineer antioipates'such automatic brake application by manually initiating an application and maintaining an effective braking until the speed of the train has been brought down below the existing'permissive speed limit,- and finally in imposing a penalty upon the engi neer at the same time in the event that an automatic application of the brakes occurs.

Having now fully shown and described any invention, what Idesire to secure by Letters Patent, is a g a 1. In an automatic train control system for railway carsor othervehicles traveling on tracks divided into-blocks,eachliaving a track circuit, car equipment comprising, a

brake-setting appliance acting automatically upon the regular or brake equipment of the car to produce a brake application, said appliance when operated maintaining the brakes applied until restored, meansfor restoring said appliance effective only after the car has been brought to a stop, apparatus ineluding a speed responsive device driven from the car Wheels and controllable to cause any one of several predetermined permissive speed limits to be set up until there is a change to a higher or lower speed limit, said apparatus makingthe change from one existing speed limit to another quickly and acting to cause operation of said brake-setting appliance if the car at any time exceeds the permissive speed limit then in effect, track elements of different construction located at selected points in each block and in the active condition if the next block in advance is occupied, car carried receiving means separately and selectively influenced inductively through an intervening air gap by said trackelements while in their active condition, and when so influenced acting to control said apparatus and set up 2. corresponding speedlimit, means on the car effective only if the engineers brake valve is placed in the service position before said brake setting appliance operates for preventing any operation thereof so long as the brake valve is kept in that service position, and other means effective only so long asthe brakes are applied to a prescribed degree for preventing initial operation of said brake setting appli ance.

sive device, sal ,havmg stick contacts closed onlygif saiddevice is energized, a normallyv closed circuit 2. In a train control system for railroads,

. car equipment comprising; in combination with theusual a r-brakeequ pment, means.

for producing. an nuton'iatie application of .the brakes and including an ,electrorespond .electroa'esponsive device for energizing said device, including sticli contacts and having a plurality of multiple branches, said device whenever; (leenergized maintaining tire; brakes applied, until, re;

stored, means for restoring said ide tice only after the car has. been .broughtito a stgop',

means conti ollableii-om thetraclmay, and incl riding a speed responsive devicfe driven I from the car wheels itorzcooperating with the I an;.automaticibrake setting appliance acting multiple branches of said normally closez circuit to provide anyone oi' aplurality of predetermined persisting speed limits and to automatically deenergize said electro-respoin,

sive device and apply the. brakes whcnerer I the ear exceeds thespeed limit then in effect,

(ill

and means effective only if the engineers brake valve is in the serviceposition for establishing. an auxiliarystick circuit for said electro-responsive .device and thereby prevent operation thereof, providing. the engineensbralie valve is placed in the service position before said electro-respousiveidevice is initial y deenergizedon account, or" excessive speed. k A;

3. ln an automatic train control system, the combination or" a railway vehicle and a traclzway therefor divided into, blocks of car-carriedapparatus adapted to restrict. the speed of the train in a block whenthenext block in :u'lvancethereof is occupied comprising, means for setting up speed limits by the trnnsm won or inductive control influent s t'roin the traclnvay, each speed liruit per sung until. followed bya lowenspeed limit or until release influence is transmitted from the traclzway, Jeans for automatically applying the brakes 01" thetrain lit the speed of the train is in excess of the l eo ess speed. of the :vehicle doesnot.,exceed thatof the curve atanypoint inj'tlie b lock, the train will beretarded sufiiciently. to have its speed fall below tlre top teeth of tliis cui-ve; means for automatically applying the brakes when 1 the permissive speed i'sexceeded; and means for, rendering said last 1nentioned" 1neans. in-

effective only ifani applicationfot the brakes .is being inannall' initiated 'or only if the brakes are. applie to a predetermined extent, ,vvl ereby the train may run at a speed above the lower i-point's but not Iabdvel the upper points/of saidspeed-distance curvewithout an automatic brake. application.

5. Juan traln.;C0ntrol. systeni for railway with an, air-b1'ake system and trave 'ng over 1. upon the airbrake system to produce an. automatic bralie application, apparatus on the vehicle including;aspeed responsive device driven fromthecar wheels and controllable to provide any one of ,three or more speed limits and actuate said; appliance if the vehicle at anytime exceeds, the speed limit then 'fqrce ineans comprising, n cer-carried receiving, element trackway elements 00- operating th w ltll lndllilively tlirouglian intervening air gap ior controlling said apparatusunder one. of its f'spee d limit condi- :;tions, sai l. trackway elements being .difier ently construc ted antl, acting separately and selectively, uponsaid apparatus through said receiving element, said brake-setting appli ance after initial operation thereof maintainin the .brakesapplied until restored, means efiective only after the vehicle has been brought to a stop for restoring said appliance, .an diineans ellective only if the engineers bgake .valve is. placed in the service position prior. to initial operation of said appliance. forpreventin the operation thereof, whereby tlie. engineerdiy taking the necessary action prior to exceeding thespeed limit may ,releasethe brakes assoon as the existing; speed flimithas been observedwithout being obliged permissive speed, and meauseiiective only: to come toa stop.-

if a brake application is being initiated or when an adequate brake application. has been eti'ected and as long as such a bral eapplica tion continues for preventing; initial operation of said brake applying means.

4t. Annautomatic train control system for railways having a trackway'divided into V blocks comprising; means for setting up suc-w 'cessive lower speed limits: in a bloclc when the next block in advance thereof isgoccnpied by transmitting inductively through an intervening air gap distinctive control influences at appropriatecontrolpoints in a block for each speed limit, such speed limit set up to 'form a step-by-step or saw-tooth v permissive speed-distance curve of a eharac lower speed limit is e'.. n1;aa; autjmatic train control system, theleombinatioli o'tja plurality of inductive influence transmitting devices along the trackway, eachjhaving a magnetic structure physically difierentfrom thatof the magnetic structures of any other of. said influence transmitting devices, each of said devices including aivindingia car-carried influence receiving device adapted to function distinctively upon-the reception of an influence from each of. the distinctive trackdevices, and means for including saidwinding in a closed deenergized circuitof low resistance.

7. .In an automatic: train control-system, a car-carried electro-ina gnetic impulse receiving means comprising, a ,yoke,.a primary and secondary coilon said .yoke,.-a circuit including asource ofenergyfor said primary coil,

a circuit for each ofsaidsecondary coils each including an electroaesponsive device, and a plurality of magnetic devices each having distinctiveiphysical characteristicsfor trans- ;mittingdistinctive control influences to said car-carried element.

-8.-= Iman impulse transmitting means for automatic train control systems, a car-carried element comprising a yoke'having- .threespaced legs on the same plane,'and energized coil on one outside leg tending-to send flux through each of the other legs, electro-responsive means associated with each of said other legs and separately operated by changes in theimagnetic fiuxin the corresponding leg, and different trackelements for cooperating with said car-carried element to produce operation of said electro-responsive means, separately or simultaneously.

9. In an automatic train control system, the combination with a car-carried impulse device including a plurality of partialmagnetic circuits, a pin 'ality of control devices operable upon a quick change in reluctance in one or more of said-magnetic circuits, andtraffic controlled trackway devices comprismg inert magnetic bodies of diii'erent physical characteristics, whereby distinctive changesof reluctance may be effected upon one or more of said magnetic circuits.

10. In an automatic train control system, the combination of vehicle-carried apparatus comprising, two control relays and three stick relays; means for: deenergizing one of said stick relays when one of said control relays is momentarily deenergized, for deenergizing another stick relay when the other of said control relays is momentarily deenergized, and for deenergizing a third stick relay. only if 'both'of said control relays are simultaneously deenerg-ized; and: of trackway devices for selectivelymomentarily deenergizing one or more of said control relays.

11. In anautomatictrainfcontrol system. a vehicle anda trackway therefor divided into blocks each provided'with a normally closed track circuit, means for transmitting controlling influences from the track to the vehicle inductively through an intervening air-gap, comprising a plurality of controllable initiating. impulse devices of' diil'erent physical construction and operating characteristics in each block for independently and selectively initiating the operation of a plurality ofcar-carried devices, aseparate resettingdevice atthe exit end of the block, said initiating devices beingamade effective by in- .terrupting. a circuit associated therewith, ,and'said resetting devices being made effective by closing acircuit including a source of energy,whereby the interruption of any of said circuits will produce an effect on the side-of safety. l 12. In'an automatic traincontrol system, the combination-of car-carried equipment for determined permissive speed limit set up has applyingthe-brakes automatically if a pre-,

been exceeded, of trackway equipment comprising blocks each havinga plurality of inductive influence transmlttin devices 0t diffe'rent physical characteristics for setting up different permissive said devices havinga a circuit Of low. resistance will prevent it from functioning, and a trackway device near speed limits, each of the exit end of such block including a coil and adapted to remove such restrictive speed limits if said coil isclosed-in a circuit with a suitable source of energy. A

13. 'lrackway equipment for transmitting inductive control influences to suitable receiving devices on a' railway vehicle for train control systems comprising, a plurality of devices along the trackway each of which is constructed to transmit a restrictive confrom that of, the

trol influence distinctive other trackway devices provided a circuit associated therewith is interrupted, and another trackway device I for transmitting a release influence if a circuit associated therewith is completed. p

14. An automatic train controlsystem comprising, a brake control device on a vehicle which if initiated will continue to apply the brakes effectively until restored, means accessible only from the ground for restoring said device, and means for enforcing a low: speed limit which the vehicle can not exceed without an automatic brake application automatically rendered effective when and so long as said restoring means is in its restoring con dition even though trafiic conditions ahead are favorable; I

15. Car-carried apparatus for automatic train control systems comprising, two normally inactive circuit interrupting devices adapted to be actuated by influences transmitted from the traclGvay, two stick relays each having a stick circuit including a contact closed only whensuch relay is in the energized position, one of said circuits including acontact of one of said circuit interrupting devices and the other stick circuit including acontactof the other circuit interrupting device, and'a third stick relay havinga stick -cir cuit including its front contact and including two contacts in multiple operated separately by said two circuit interruputing devices, wherebymomentary operation of one of said circuit interrupting devices drops one of said stick relays, themomentaryoperation of the other circuit interrupting device. drops another stick relay and momentary simultaneous operation ofboth of said circuit interrupting devices drops. the third-relay.

' 16. Car-carried apparatus'for automatic train control; systems comprising, a stick relay having a stickcircuit including a front contact of, said relay which if deenergized restriets thespeed of the vehicle, may travel coil which if closed in LOO without incurring an automatic brake; appliu cation; means for applying the-brakes it the speed imposed with the-stick relayinthe dey energized position is exceeded; ineansfor'deenergizing said stick relay including an inductive influence receiving device provided with a secondary coil in which a'current is induced by inductive communication of said inductive'connnunicating device with a suit- "able trackway 'device,-and means for picking up said stick relay including an armature adapted'to be actuated by a flux'producing means disposed along the trackway.

l7. Car-carried apparatus for automatic train control systems comprising, a Si3l(l-2l)- lay normally energized by a stick circuit, including a "front contact of said relay, means acting on the usual air brake systeinfor' applying the brakes it the vehicle exceeds predetermined speed limits when said'relay'is deenergized. means for deenergizing said stick relay, and means for again picking up said stick relay by momentarily closing a pick-up circuit, said pick-up circuit including acontact closed if an armatureadapted to be actuated by a flux producing means disposed along the .trackway when"acti've.

18. Cancarried equipmentfor automatic train control systems comprising, a. normally energized electrically operated stick brake control device having a circuit including a contact operated by said device and closed only when said device is energized and which device if deenergized eli'ects an application of the brakes by acting on the usual air brake system, circuit controlling means in series with said circuit for breaking said circuit if a certain speed limit is exceeded including means controlled from the trackway in accordance with tratlic conditions ahead for abruptly changing such speed limit, two contacts in multiple with'said circuit controlling means one of which is closed when the engineers brake valve is in a brake applying position and the. other of which is closed when a full service. brake application is effective, whereby it and only if the engineer anticipates the excessive speed by the initiation of a rnanual b -akc application an automatic brake application may be prevented.

19. Car-carried equipment for automatic train control systems comprising, a normally energized electrically operated stick brake control device having a circuit includingfa contact operated by said device and closed only when said device 'is energized and which if deenergized effects an application of the brakes by acting on the usual air brake system, circuit controllingmeans in series with said circuit for breaking'saidcircuit if acertain speed limitis exceeded including means controlled from thetrackway in accordance with trafiic' conditions "ahead for abruptly cliai gin'g"siic'li speed limit, two contacts in multiple Withsaid circuit controlling means one of v which is closed when the engineers is and the otherof which is closed when a' fullservice' 'brake'applicationhas been made cited 1 tive, whereby it and only if the engineer-antic ipates the excessive speed by the initiation'of a manual brake: Iapplication an automatic brake" application may be prevented, and

i. means .i'or-penalizing the engineer each time arr-automatic brakeapplication occurs; i 20. In an automatic train control system, the combination of a railway vehicle and a trackway therefor divided-into blocks, of

car-carried apparatus adapted to restrict the v speed of the train in a block if the next block in advance is occupied comprising,"n1eans for setting n p diiierent permissive' speed==li1nits by correspondingly distinctive control influcnccs transmitted inductively from the trackwa-y, each speed limit persisting until followed by a lowerspced limit or un'til re lease influence is transmitted 'fi'oinlthe tracle way, means for automatically applyingthe brakes o f the vehicle if the speed then existing ot' the vehicle is in" excess 0f pelinissive' speed, and means for preventing rele'ase oti brakeivalv e'is infa brakeapplying position su chbrake application until the train has been brought to a stopunless' the engineer has initiated a manual brake application-before the permissive speed ofthe vehicle was exegded; a. Ill. V

21, In an intermittent indncti e impulse transmitting means for train 'c'onti' ol systen is capable of giving a plurality of- -'conti'ols, a car-carried receiver comprising a magnetic body providing two separate partial magnetic circuits, an energizing coil commonte said magnetic circuits acting to send'fiux through both, coils separaetelyassociated inductively with said magnetic circuits, electro-responsive devices on the car separately connected to'said coils and independently influenced by the voltages induced "in said respective coils by flux ehanges in the corres onding magnetic circuits,'a trackway element cooperating with said receiver 't'o'reduce the reluctance of oneof said magnetic circuits, another track-' way element acting to reduce the reluctance of both of said magnetic circuits'simultaneously, and windings on said trackway elements and control circuits therefor governed inyaccordance with ti'afiic'conditions. v

22. An automatic train control system comprising, vehicle carried "apparatus including a brake control device,'a: speed-responsive device drive'n from the wheels "of the'vehic le, arolay on the vehicle, ine'ans'effective when said relay is' de energized"for applying the brakes ot' 'thefirainby actuating said brake 'control'device if the 'actual speed as manifestedioy -said speed responsive device "exceeds a predetermined speed limitjmeansf partly on thevehicle and partly along thetrackway for transmitting control influenc'es from 'the trackway totl'ie"vehicle inductively through an intervening air gap in accordance with traffic conditions ahead for energizing and deenergizing said relay, manually operable means which it moved to its active position will prevent said brake control device being rendered active, and means for preventing said manually operable means being left in its active position permanently consisting of means for tie-energizing said relay to impose said speed limit so long as said manually operable means assumes its active position.

23. An automatic train control system c0111- prising, a normally energized electrically operable brake control device on the vehicle which if operated automatically co-operates with the air brake system of the vehicle to produce an automatic brake application, said device once operated preventing release of the brakes until specially restored, means accessible only from the ground for restoring said device after operation thereof to permit release of the brakes, apparatus on the vehicle including a speed responsive device driven from the Wheels of the vehicle and controlled inductively through an intervening air gap from the trackway in accordance with tratfic conditions, said apparatus automatically actuating said brake control device whenever the vehicle exceeds a predetermined speed limit under unfavorable trailie conditions, and automatic means for preventing such operation of said brake control device notwithstanding the excessive speed of the vehicle only if the engineer initiates and completes a predetermined manual application of the brakes prior to exceeding said speed limit.

24. An automatic train control system comprising, a brake control device on a vehicle, ineluding a normally energized electropneumatic valve adapted when de-energized to cause an automatic brake application, said device When once operated continuing in operation and preventing release of the brakes until specially restored, means effective only it the vehicle has been brought to a stop for restoring said device, a relay on the vehicle, means partly on the vehicle and partly on the track for controlling said relay automatically in accordance with traific conditions, means on the vehicle including a speed responsive device driven from the wheels thereof and governed by said relay for controlling said brake control device, said last mentioned means acting while said relay is (lo-energized to actuate the brake control device whenever the running speed of the vehicle exceeds a predetermined speed limit, an engineers brake valve, pressure responsive means actuatcd only if a predetermined brake application is in force, and means effective only if said engineers brake valve is in a brake applying position or said pressure responsive means is actuated prior to the automatic operation of said brake control device for preventing operation thereof in spite of the excessive speed of the vehicle.

In testimony whereof I hereto allix my signature.

lVINTHROP K. HOW'E. 

